bbbb bbdd bbdo bbrc bcbc bccc bcor bcru bcuc bd-r bdbc bddc bobb bobo bobu bock boco bocu bodb bodo bodu boko boku boob booc bood book boor bor- bord bork boro borr boru boud bouk bour brcb brdo brkb brob broc brod brok broo bror brou brrr bruc brud bubb bubo bubu bucc buck buco bucu budb budd budo budu bukk buko buku bur- burb burd burk buro burr buru c-bo c-cd cbbc cbcc cbcr cbcu cbdb cbdc cbdo cbko cbkr cbrd ccbc cccb cccc cccu ccdc ccdr ccob ccoc ccod ccrc ccuc cd-r cddb cddr ckbc ckck ckco ckdo ckdu ckob ckoc ckoo ckor ckrc ckrd cobb cobo cobu cock coco cocu codd cok- coko coob cood cook cor- corb corc cord cork coro corr coub coud couk cour crbc crbu crcc crcr crdc crkc crob croc crod crok croo cror crub crud cruk cub- cubb cucc cuck cuk- curb curd curo curr d-bo dbcc dcbc dccb dccc dccu dcdb dcrk dddd ddoc ddrc ddub dkdc dobb dobu dock doco docu dod- dodd dodo doko doob dood dook door dorc dord dork doro dorr doru doub douc doud douk dour drbc drob drod drou drub druk druu dub- dubb dubc dubu duck duco dudd dudo dudu duku duo- durk duro duru duur kbbb kbbc kbbd kbbk kbbo kbbr kbbu kbcb kbck kbco kbcr kbcu kbdb kbdo kbdr kbkb kbkk kbko kbkr kbob kboc kbod kbok kboo kbrb kbrc kbrd kbrk kbro kbru kbub kbuc kbud kbuk kbur kbuu kcbc kcbd kcbk kcbr kcbu kccb kccc kccd kcck kccr kccu kcdc kcdd kcdr kcdu kckc kckk kcko kckr kcob kcor kcou kcrc kcro kcrr kcru kcub kcuk kdbb kdbr kdcc kdcd kdco kdcr kddb kddc kddd kddk kddr kdkb kdkd kdkk kdko kdkr kdoc kdok kdrb kdro kdub kduc kdur kkbb kkbd kkbo kkbr kkcb kkcd kkck kkco kkcr kkdc kkdd kkdo kkkk kkob kkoo kkor kkrb kkrc kkrk kkro kkrr kkuu kobb kobc kobk kobo kobr kobu kocb kocd kock kodk kodo kodu kokb kokc kokk koko kokr koku koob kooc kook kooo koor koou korb korc kord kork koro korr koru koub kour kouu krbb krbd krbk krbr krcb krcc krcd krco krcu krdc krdd krdo krdr krdu krkc krkd krkk krko krkr krku krob kroc krod krok kroo kror krrb krrc krrk krro krrr kruc kruk krur kubb kubc kubd kubo kubr kubu kucb kucc kucd kuco kucr kudd kudo kudu kukk kuku kuok kuoo kurb kurd kurk kuro kurr kuru kuub kuuk kuur kuuu obbo obkb obok obor obro ocbc occc ocro ocrr ocur odbo oddd odoo odor odou odur okcu okko okok okor okro okur oocr ooku oooo oord orbb orbo orbu orco ordo ordu orko oro- orok oror orro orub oucc oudc our- ouro ouu- rbbb rbbr rcbc rcbo rccb rccc rcdc rcrd rdoc rob- robb robo robu rocc rock roco rodd rodo rokk roko rokr roku roob rood rook roor rorc rork roro roru roub roud rouk rrrr rubb rubu ruck rudd rudo rukk ruku ruok rurc rurd ruro ruru ruud ubbo uboc ubod ubud ucbc ucdc ucdd ucrc udbc udoo uduk ukcc ukko ukok ukrc ukur uocc uor- urdu uro- urok uroo uruk urur uuoc uuuu